The invention relates to a belt buckle including locking status detection, comprising a switching contact and a mating contact, the switching contact and the mating contact being electrically conducting parts of a switch.
Locking statue detections in belt buckles for seat belts in automotive vehicles serve for identifying whether the vehicle occupant is properly buckled. For this purpose, it is usually checked whether a belt tongue of a seat belt is locked in the belt buckle. This information is used for optical or acoustic buckling reminder or for a different safety system.
A widespread principle for detecting the locking status is constituted by an electric contact switch which is activated upon insertion of the belt tongue into the belt buckle.
Belt buckles having a micro-switch actuated by the inserted belt tongue are generally known. In this case the electric contact is closed by a resilient contact tab which is made to contact a mating contact. The contact force of the micro-switch corresponds to the spring bias of the mechanical contact tab. It is a drawback of these systems that the contact force is defined by the material and the wall thickness of the contact tab. Further, the contacts of the micro-switch get easily stained which may result in an impaired functioning of the micro-switch.